Fourth Grade Math Vocabulary 1. Expression- numbers and symbols that represent a mathematical relationship An example of an expression is (4 + 5). 4+5 2. Equation- a statement that two mathematical expressions are equal An example of an equation is 90 ÷ 9 = 10. 4+5=9 3. Division-the operation of separating into equal groups. When I divided a group of 6 cookies among 2 friends, each had a smaller group of cookies. 4. Remainder- the amount left over after dividing into equal groups One of the remainder when 7 is divided into 2 equal groups. 1 5. Decimal Number- A number which contains a decimal point that separates the whole number and the fractional part The decimal number is read “one AND four-tenths.” 6. Tenth- one out of 10 equal parts One-tenth can be written as a decimal or fraction. 7. Hundredth- one out of 100 equal parts The decimal 0.01 has a 1 on the hundredths place. 8. Improper fraction-a fraction with a numerator greater than or equal to its denominator An improper fraction is equal or greater than 1. 5 3 2 9. Mixed Number-a number with a whole number and a fraction One and two-thirds is a mixed number. 2 3 1 10. Acute angle- An angle smaller than right angle The letter “V” forms an acute angle, because it is smaller than a right angle. 11. Right angle- an angle formed by two perpendicular lines Right angles can be measured with the corner of computer paper. 12. Obtuse- An angle greater than a right angle The letter ”Y” forms two obtuse angles that are larger than right angles and one acute angle. 3 13. Parallel- lines or segments that are always the same distance apart and will never intersect The letter “H” has parallel segments. 14. Perpendicular- segments or lines that intersect at right angles The letter “T” forms perpendicular segments. 15. Translation- a transformation that slides a shape to a different position without rotating or flipping it A translation slides an object. 16. Reflection- a transformation that flips a shape so it is a mirror image of the original shape A reflection flips an object. 4 17. Rotation- a transformation that turns a shape around a central point A rotation turns an object around a center point. 18. Parallelogram- a four-sided polygon with 2 pairs of parallel and congruent sides A parallelogram looks like a slanted rectangle. 19. Elapsed time-the amount of time that passes between two given times To find elapsed time, I use time-on-a-line as a strategy. 20. Conversion-the renaming of one unit of measurement to another equivalent unit of measure 1 foot Use a table to make a conversion from feet to inches. 12 inches 5